1. Technical Field
The invention relates generally to the field of wireless Internet communications. More specifically, the invention is directed to an improved modular wireless Internet access communications system designed to extend wireless access up to fifteen miles beyond the physical limits of DSL or cable technologies, through the integration of specialized wireless hardware devices, firmware, and protocols.
2. Description of Prior Art
Wireless communication systems are known in the art. However, the current art is limited to short range wireless Internet access due to technical and regulatory limitations. The effective transmission power of radio frequency devices is measured as EIRP (Effective Isotropic Radiated Power). EIRP takes into account the power output of a transmitter, gains that an antenna provides, and losses from cabling. The Federal Communications Commission restricts the total EIRP of a wireless communication device to minimize radio frequency signal interference. The gain of an antenna represents how well it increases effective signal strength, measured in dBi (decibels relative to an isotropic radiator). Higher values of antenna dBi represent a greater range of effective transmission and reception of radio frequency signals; the latter due to greater sensitivity and added gain to incoming radio signals that are naturally weaker than transmitted signals. The current art uses relatively high powered amplifiers to make up for losses occurring through the cabling (up to 90% of the signal strength of radio frequency signals may be lost in just a 10-foot run of cable). This increases cost and does not address a fundamental problem of wireless networks; the transmit-versus-receive signal imbalance inherent in nearly all radio systems. The transmitted signal strength is generally several hundred times higher than that of the received signal. Range is as dependent on receive sensitivity and gain as it is on transmitted signal strength. Increasing only the gain in transmission or increasing transmit and receive gain equally rapidly reaches the power limits imposed by the FCC, restricting overall range.
The prior art discloses various wireless communication devices which share some similar characteristics with the present invention, though which fail to accomplish the primary objective of extended range wireless Internet access in a simple, low cost modular system.
Thomas, et al., Integrated Active Antenna For Multi-Carrier Applications, U.S. Pat. No. 6,812,905 (Nov. 2, 2004) discloses a system incorporating a plurality of antenna elements and power amplifiers. This system mounts an amplifier closely adjacent to each associated antenna element to minimize power loss. However, it requires one amplifier per antenna, and further requires a large number of antennas arranged in an array. These limitations result in a more complex and costly solution than the present invention. It also does not achieve the extended range of the present invention.
Judd, Antenna Structure And Installation, U.S. Pat. No. 6,583,763 (Jun. 24, 2003) also discloses a plurality of antenna elements and power amplifiers, with each amplifier oriented in close proximity to an antenna. However, the disclosed invention physically separates multiple radio transceivers, locating some on a tower and others at the base of the tower, thereby failing to capture the efficiencies of locating the transceivers proximate to the antennas.
Higgins, Wireless Internet Access System, US Patent Application 2003/0185169 (pub. Oct. 2, 2003) discloses a roof-mounted water-tight enclosure in connection with an antenna, containing a wireless modem and a power splitter. The disclosed invention, however, relies on a multiplicity of access points feeding back to a higher access point to the wired gateway. It further does not use routers at the access points.
Quayle, Cellular wireless Internet access system using spread spectrum and Internet protocol, European Patent Application 1098539 A2 (pub. May 9, 2001) discloses a high speed wireless Internet access system incorporating a plurality of cellular base stations located a ground level, for receiving/transmitting over a relatively short effective range of not more than 0.5 miles.
Dodd, et al., Antenna System, Patent Cooperation Treaty Application WO 2002/082665 A2 (pub. Oct. 17, 2002) discloses a dual antenna system with a high gain antenna for receiving signals and a low gain antenna for transmitting signals, together with a switched receiver/transmitter.
The above-cited prior art is easily distinguished from the present invention. The ability of the present invention to be configured without an amplifier, due to the minimization of signal strength loss, distinguishes it from the systems cited, each of which requires an amplifier. The present invention does not require large antenna arrays. The prior art does not capitalize on the efficiencies to be gained from placing the radio transceiver in close proximity to the antenna. These and other features of the present invention, described below, disclose a novel and useful invention.
It is an objective of the present invention to provide low cost, long range wireless Internet access.
It is a further object to provide a modular wireless communication system which may be customized by using one or more of the modules to individual customer needs.
It is yet a further object to provide a wireless communication system which can be mounted in a variety of environments, such as atypical structures without traditional power supplies, or with exposure to weather extremes.
Other objects of the present invention will be readily apparent from the description that follows.